1. Field of the Invention
The present invention relates to a cooling apparatus that cools a heat-generating element such as a central processing unit (CPU), a large-scale integrated circuit (LSI), a power semiconductor, etc.
2. Description of the Related Art
In recent years, the density of generated heat in heat-generating elements such as CPUs, LSIs, power semiconductors, etc., has increased, and increases in cooling performance of the cooling apparatus are being sought.
In consideration of such conditions, conventional cooling apparatuses have been proposed in which a liquid coolant supplying flow channel and a liquid coolant discharging flow channel are formed inside a cooling substrate such that flow channel directions are parallel and so as to be separated by a predetermined distance in a direction that is perpendicular to the flow channel directions, and cooling flow channels are formed inside the cooling substrate so as to communicate with the liquid coolant supplying flow channel and the liquid coolant discharging flow channel so as to have respective flow channel directions perpendicular to the flow channel directions of the liquid coolant supplying flow channel and the liquid coolant discharging flow channel, the cooling flow channels forming two layers vertically and being arranged at a predetermined pitch in the flow channel directions of the liquid coolant supplying flow channel and the liquid coolant discharging flow channel (see Patent Literature 1, for example).
In this conventional cooling apparatus, one switching semiconductor element and one diode are disposed in series along the direction of circulation of the liquid coolant in the cooling flow channels on a front surface and a rear surface of the cooling substrate. Thus, it is claimed that the switching semiconductor elements or the diodes can be cooled efficiently, and cooling capacity can be increased, because the switching semiconductor elements or the diodes, which generate heat, are constantly cooled by liquid coolant from near the liquid coolant supplying flow channel that is in a sufficiently cooled state that has not risen in temperature.